[PATCH] drm/i915/display: A check on mode->clock, if it exceeds max_dot_clock

[Nischal Varide]

Making sure that the  mode-clock is not greater than the
max_dot_clock freq.This patch will prevent attempts from
userspace to modeset with mode->clock greater than
max_dot_clock freq.

Signed-off-by: Nischal Varide <nischal.varide at intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c   | 10 ++++++++++
 drivers/gpu/drm/i915/display/intel_hdmi.c |  3 +++
 2 files changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 7400d6b4c587..e603b7c01d27 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2045,6 +2045,16 @@ intel_dp_compute_config(struct intel_encoder *encoder,
 	if (intel_dp_hdisplay_bad(dev_priv, adjusted_mode->crtc_hdisplay))
 		return -EINVAL;
 
+	if (!intel_dp_can_bigjoiner(intel_dp) &&
+			(adjusted_mode->clock > dev_priv->max_dotclk_freq))
+		return -EINVAL;
+
+	if (intel_dp_can_bigjoiner(intel_dp) &&
+		(adjusted_mode->clock >  (2 * dev_priv->max_dotclk_freq)))
+		return -EINVAL;
+
+
+
 	/*
 	 * Try to respect downstream TMDS clock limits first, if
 	 * that fails assume the user might know something we don't.
diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
index 02f8374ea51f..50603806a964 100644
--- a/drivers/gpu/drm/i915/display/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
@@ -2247,6 +2247,9 @@ int intel_hdmi_compute_config(struct intel_encoder *encoder,
 	if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
 		return -EINVAL;
 
+	if (adjusted_mode->clock > dev_priv->max_dotclk_freq)
+		return -EINVAL;
+
 	pipe_config->output_format = INTEL_OUTPUT_FORMAT_RGB;
 	pipe_config->has_hdmi_sink = intel_has_hdmi_sink(intel_hdmi,
 							 conn_state);
-- 
2.36.0